In automotive use and the like, it is common to provide weld nuts and pierce nuts for attachment to sheet metal parts to provide a means for fastening bolts, screws and the like.
It has heretofore been suggested that a self-flanging nut construction may be made by utilizing a tubular body having a laterally extending flange at one end and an opening therethrough, said opening having a first portion and a second portion of differing cross sectional areas, the first portion being formed with a thread and the second portion defining a riveting flange. A plurality of circumferentially spaced serrations or ribs are provided on the periphery of said body adjacent said flange. When the nut is placed adjacent a sheet metal body having an opening therein with the opening in alignment with the opening in the nut and the nut is forced against said plate, the metal surrounding said opening in said plate is first deformed axially of the opening to form a tubualr portion and thereafter the riveting flange is deformed laterally outwardly over the end of the tubular portion formed on said plate.
Among the objects of the invention are to provide an improved nut, joint and method and apparatus for making the joint, wherein high strength is obtanined with minimum metal wherein excellent torque characteristics are provided, wherein the nut is readily located and properly positioned with respect to the metal part and wherein the same nut can be utilized for different gauge metal parts.